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Subtitles and captions with ggplot2 v.2.2.0

Back in March 2016, I wrote about an extension to the R package ggplot2 that allowed subtitles to be added to charts. The process took a bit of fiddling and futzing, but now, with the release of ggplot2 version 2.2.0, it’s easy.

Let’s retrace the steps, and create a chart with a subtitle and a caption, the other nifty feature that has been added.

A basic plot

You may have heard that run scoring in Major League Baseball has been down in recent years…but what better way to see if that’s true than by plotting the data?

For the first version of the plot, we’ll make a basic X-Y plot, where the X axis has the years and the Y axis has the average number of runs scored. With ggplot2, it’s easy to add a trend line (the geom_smooth option).

So now we have a nice looking dot plot showing the average number of runs scored per game for the years 1901-2015. (The data for the 2016 season, recently concluded, has not yet been added to the Lahman database.)

With the basic plot object now created, we can make the changes in the format. In the past, the way we would set the title, along with X and Y axis labels, would be something like this.